FIFTY-FIRST CONGRESS. Sess. I. Ch. 1243. 1890. 565 way shall not be permitted; and also that piers which will roduce cross—currents or bars dangerous to navigation shall not lbe constructed; and if after construction any piers or accessory works are found to produce the above-mentioned effects, or if any riprapping or other protection prohibited by this section is found to exist, the nuisance shall be abated or corrected under the direction of the Secpetapy of War, at tthe expgn}se_3f the company or persons owning, conro ing, or opera ing said r1 ge. _ Sec. 5. That the approaches to said bridge shall be so designed and Avprwchenconstructed as not to interfere with the free discharge of said river in seasons of Hood; and any encroachment on the high-water cross- Encroachment by section bly PIBTS, solid embankments, or otherwise which will result pi°'“* °“· ‘ p1_(pnduhy]1accplp)ratipg t(he high-water current at the site of the ri ges a no ea owe . Sec. 6. That any corporation, company, or persons owning, con- Amswmvigsucn. tml1in5i or operating the bridge bui t under the authority of this act sh build and maintain at all times, as accessory works to such bridge, such booms, piers, dikes, ard fences. and similar devices as mgy be necessary to insure at ah times a permanent channel for a su cient distance above and below the bridge site, and for the guidiu of rafts, steam-boats, and other water-craft safely under or through said bridge; and if at any time after the construction of the bridge and its accessory works the approaches to draw openings, channel-spans, or raft-passages in said ridge are found to be dangerous or diilicult of access by river traffic, the Secretary of War may, upon the recommendation of the Chief of Engineers, United States Army, order the corporation, company, or persons owning, controlling, or operating said bridge to construct, under his directions, and to maintain such additional sheer-booms, dikes, and other Additmslakk. 'devices as will obviate the diiiiculty mentioned, which additional _sheer-booms, dikes, and other devices shall be built and maintained at their own expense by said company or persons; and that said company or persons shal mamtain, at their own expense, from sunset to sunrise throu hout the season of nav1gation, such lights and ¤z¤¤¤»¤¤¢· other signaf on said briplge as nijay be required by the Lig t-House Board for the securit o navi a ion. Sec. 7. That the biiidge authorized to be constructed by this act mggcurity or navigashall be located and built under and subject to such regulations for the security of navigation on said river as the Secretary of War BS¤;r¤¤¤p of Wtirow shall prescribe; and to secure that object said corporation shall sub- pH.K._°Z,Z° °°° °’ mit for his examination a design and drawings o the bridge, piers. approaches, and accessory wor s, and a map of the location, giving, for a s ace of at least three miles above an one mile below the proposed location, the tqpography of the banks of the river and the shore-lines at high an low water. This map shall be accompanied Mun by others drawn on the scale of one inch to two hundred feet, giving, for a space of one-half a mile above the line of the proposed bridge and one- uarter of a mile below, an accurate representation of the bottom di the river, by contour lines five feet apart, determined by accurate sounclings, and also showing over the whole width of this part of the river the force and direction of the currents at low water, at high water, and at least one intermediate stage by triangulated observations on suitable floats. The maps shall also show the location of other bridges in the vicinity, an shall give such information as the Secretary of War may require for a full and satisfactorv understanding of the subject; and the construction of the proposed bridge shag pottpe céomxmenceclfuppil the location and plans thereof are a rove e ecre ary o ar. Sec. 8. Thgt) any bridge constructed under the authority of this oenmisupmssm. act shall be built under the general supervision of the Secretary of War, and no chan es or alterations in plans shall be made during Chanzesinplm the construction og said bridge or after its completion, unless said
